An endocutter is a surgical tool that staples and cuts tissue to transect that tissue while leaving the cut ends hemostatic. An endocutter is small enough in diameter for use in minimally invasive surgery, where access to a surgical site is obtained through a trocar, port, or small incision in the body. A linear cutter is a larger version of an endocutter, and is used to transect portions of the gastrointestinal tract. A typical endocutter receives at its distal end a disposable single-use cartridge with several rows of staples, and includes an anvil opposed to the cartridge. The surgeon inserts the endocutter through a trocar or other port or incision in the body, orients the end of the endocutter around the tissue to be transected, and compresses the anvil and cartridge together to clamp the tissue. Then, a row or rows of staples are deployed on either side of the transection line, and a blade is advanced along the transection line to divide the tissue.
During actuation of an endocutter, the cartridge fires all of the staples that it holds. In known endocutters and linear staplers, wedges are moved longitudinally, where each wedge sequentially encounters a plurality of staple drivers during its travel. Those staple drivers convert the longitudinal motion of the wedges into vertical motion of the staples, driving the staples upward into an anvil. The wedges are simply solid pieces of metal or other material shaped in a way to facilitate contact between the wedges and the staple drivers. Depending on the amount of tissue clamped between a cartridge and an anvil of an endocutter, some of the staples may deploy from the cartridge away from clamped tissue, such that those staples close but do not close into tissue. Because the staples are made of biocompatible material such as stainless steel or titanium, are small compared to the size of bodily structures, and are closed or generally closed at the completion of deployment, these staples are simply released into the patient, where they reside harmlessly just as do the staples that deployed into tissue.
The use of the same reference symbols in different figures indicates similar or identical items.